Process of making metallic duplicate sound-records.



F. L. DYER.

PROCESS 0F MAKING METALLICv DUPLIGATB SOUND RECORDS.

APPLICATION FILED 11111.27. 1908.

1,002,659, A v Patented Sept. 5, 1911.

UNITED sTATEs PATENT oEEIoE.A

FRANK L. D'YER, 0F MONTCLAIR, VNEW JERSEY, ASSIGNOR, BY MESNEASSIGNMENTS, TO THOMAS A. EDISON, INCORPORATED, OF WEST ORANGE, NEWJERSEY, A vCOR- PORATION OF NEW JERSEY.

Specification of Letters Patent.

- Patented sept. 5, 1911.

Application led January 27, 1908. Sen'al No. 412,741.

To all whom it may concern:

Be it known that I, FRANK' L. DYER, a citizen of the United States,residing at Montclair, county of Essex, and State of New Jersey, haveinvented a certain new and useful Process of Making Metallic DuplicateSound-Records, of which the followin is a description.

Iy invention relates to an improved process for making metallicduplicate sound records, whether of cylindrical or disk type, and myobject is to provide a very simple process which can be carried 'out ona commercial scale for the production of an unlimited number of accuratemetallic duplicates from a sin le mold or matrix. Metallic duplicates tus made will permit the effective production and reproduction of arecord of very great fineness, say, of three'- thousandths of an inch,or less in width.

The invention resides in the fact that by producing on the recordsurface of the matrix or mold an excessively thin coherent layer ofso-called cement copper, andby electroplatingthe metal thereon, theadhesion between the particles of cement copper and between the latterand the matrix or mold, on the one hand and the electrodeposited met-alon the other, is so slight as to ermit the ready separation of` theelectrogeposited metal, after which any of the cement copper adheringthereto, orto the mold, can be easily rubbed off. When the mold ormatrix is of a tubular form, the electrodeposited metal will exist as ashell and can be removed by collapsing the shell inwardly, but when vthematrix or mold is in the form of a fiat disk, the electrodeposited metalcan be freely stripped' olf of the same. The shell or disk obtained inthis way, carrying the representation of the rec ord to be duplicated,is supported on a suitable foundation.

In order that the invention may be better understood, attent-ion isdirected to the accompanying drawing, forming part of thisspecliication, and in which* Figure 1 is a sectional view on an enlargedscale, of a portion of the matrix or mold with its film of cement copperdeposited on the record surface thereof, and with the electrodepositedlayer constituting the record surface of the duplicate; Fig. 2 across-sectional view illustrating the manner lbeing either tubular or oftional view of the composite cylindrical record with a metallic surface.

In the above views, corresponding parts are represented by the samenumerals of reference.

The mold 1, is of any'suitable character, disk form, and is providedwith theA usual negative record surface, as shown. 'I place the mold ina suitable cobalt plating bath, preferably a concentrated solution ofcobalt chlorid with cobalt anodes, and plate on the record surface anlexceedingly thin film or blush of cobalt 2,which may be less than .0001of an inch in thickness. During this plating, the mold is preferablyrot-ated so as to make the plating uniform. Themold is now washed and isthen. immersed in a solution of copper sulfate, the reaction causing thecobalt to go into the solution and the copper to be deposited asminutely granular', but slightly adhesive form. Preferably, theimmersion iscontinued only long enough to result in the covering of thecobalt lilm with a perfect layer of cement copper, so as to leave a partof the cobalt film still intact. If all the cobalt were dissolved in thecopper sulfate bath, there might be danger of the electrodeposited lmbeing plated imperfectly at rst, since it is deposited under'a conditionof tension, but it will be understood of course, Y

that if desired, the entire film of cobalt may be reduced to cementcopper. Instead of first depositing on the mold a thin blush of cobalt,as explained, any other metal might be used in connection with whichsubstantially the same reactions take place, for instance, iron. Havingcoated the record surface of the matrix or mold with 'an excessivelythin iilm of cement copper, as explained, I now electroplate upon suchfilm, a heavier deposit 3, of a suitable metal, upon which the record isto be made. This is preferably nickel, owing to its non-oxidizingproperties. Preferably, during the operations Which have been described,the matrix or mold, except for its record surface vis protected by acoating of varnish or parafn,

or some similar material, so that the plating operations will beconfined to the record surface.` The Shell or disk of nickel or othercement copper iny a metal, Vwhich has thus been formed (depend-I ofpotash,

ing, of course, whether the mold is tubular or disk-like) is removed,which can be readily effected, owing to the slightly adhesive character-ofv the film of cement copper. When the mold'is tubular, the` shell ispreferably collapsed, asshown in Fig. 2. Having obtained a shell or diskof electro-plated metal, carrying an accurate copy of the record to beduplicated', it is now supported on a suitable foundation 4, ofplaster-of- Paris, or papier mch. It .will be understood that in orderto facilitate the stripping of the electrodeposited duplicate from thematrix, the matrix with the electroplated depo ft inl position, may besubjected to a thirty to forty per cent. solution of cyanid by which thecement copper will be dissolved, so as to entirely free theelectrodeposited layer, butordinarily this is not necessary, since theadhesion, of the particles of cement copper is so slight as to permitthe electrodeposited layer to be readily stripped from the matrix ormold.

Having now described myl invention, what I claim as new and desire tosecureA by Letters fatentis as follows j 1. A process fory makingmetallic duplicate copies of sound records, which consists inapplying tothe record surface of a matrix or mold, a very thin film of granularslightly adhesive cement copper, in electroplating a thin and relativelynon-oxidizablev metal thereon, and in nally separating the electrovdeposited metal from the matrix or mold, substantially as and for thepurposes set forth.

2. A process for makin metallic duplicate copies'of sound recor s, whichconsists in applying to the recordsurface of the Imatrix or mold, an-excessivelythin film of cobalt, in then subjecting the deposited filmto a copper solution to thereby result in the formation ofgranulanslightly adhesive cement copper, in electrodepositing on the celment copper a heavier layer of metal, and in finally removing thelatterdeposit, substantially as and for the purposes set forth.

3. A process `for making metallic duplicate copies of sound records,which consists in rotating a matrix or mold in -a cobalt plating bath,and in depositing on the record` surfaceof the matrix or mold anexcessively thin film of cobalt, in then subjecting the cobalt film to acopper solution, result-ing in theformation of granular slightlyadhesive cement copper film, in then electrodepositing ametal thereon,and in finally removing'the reo electrodeposited metal, substantially asand for the purposes set forth.

4. A process for making metallic duplicatecopies of sound records, whichcons1sts in el'ectroplating on the record surface of a matrix or mold anexcessively thin filmvof cobalt, in subjecting said film to the effectof a copper solution so as to convert a part only of the lm to granularslightly adhesive cement copper, in then electroplating a metal thereon,and in finally removino the electrodeposit, substantially as and for thepurposes set forth.

5. YA process for making metallic duplicate copies of sound records,which consists in applying to the record surface of the matrix or mold,an excessively thin film of a metal having the power to replace copperin a copper solution, in then subjecting the deposited film to a coppersolution to thereby result in the formation of granular slightlyadhesive cement copper, in electrodepositing on the cement copper aheavier layer of metal, and in finally removing the latter deposit,substantially as and for the purposesset forth.

6. A process for making metallic duplicate copies of sound records,which consists in rotating a matrix or mold in a plating bath and indepositing on the record surface of the matrix or mold an excessivelythin lm of the metal the salt of which is in solution in the bath, themetal being one having the power to replace copper in a copper solution,in then subjecting the film so deposited to a copper solution resultingin the formation of a granular slightly adhesive cement copper film, inthen electro-depositing a metal thereon,.and in finallyremoving ltheelectro-deposited metal, substantially asl and for the purposes setforth.

' 7. A process for makin metallic duplicate copies of sound recor s,which consists in electro-plating on the record surface of a matrlx ormold an excessively thin film of a metal having the power to replacecopper in a copper solution, in subjecting said film to the effect of acopper solution so as to convert a part only of the film to granularslightly adhesive cement copper, in then electroplating a metal thereon,and in finally removing the electro-deposit, substantially as and forthe purposes lset forth.

8. A process for making metallic dupli- .cate copies of sound records,which consists 1n applying to the record surface of the tubular matrixor mold an excessively thin film of a 'metal having the power to replacecopper in a copper solution, in then subjecting the deposited film to acopper solution to thereby result in the formation of granular slightlyadhesive cement copper, in electrodepositing on the cement copper aheavier layer of metal to form a positive record, and in finallyremoving the latter from the mold and the cement copper by collapsingthe same, substantially as and for the purposes set forth.

9. A process for makin metallic duplicate colpies of sound' recordswhich consists in app ying to the record surface of a matrix or mold, avery thin film of granular slightly adhesive cement copper, and eleetro-This specification signed and witnessed plating a thin deposit of metalthereon, in this 25 day of Jan. 1908. dissolving out the cement copperby a soluf tion of cyanid of potash, and finally sep- FRANK L' DYER' 5arating the electro-deposited material from Witnesses:

the matrix or mold, substantially as and for ANNA R. KLEHM,

the purpose set forth. FRANK D. LEWIS.

